A like-for-like roof window replacement in Ipswich costs £1,150 to £1,650 for a single unit up to MK06, £1,450 to £2,100 for a PK10 or larger, and £2,000 to £2,900 for two units on the same slope. Those are installed, supply-and-fit prices for swapping an existing window without touching the rafters. Access and making-good are the main variables on top.
What “like-for-like” means, and why it is the affordable job
Like-for-like means the existing structural opening stays exactly as it is. The old unit comes out, a new one goes into the same trimmed hole, and the rafters are never cut. Because the opening is already formed and the ceiling reveal already exists, there is no structural work and Building Control involvement is limited to the thermal requirement rather than anything structural. That is why it is a one-day job and why it costs a fraction of cutting a brand-new opening. Most replacements across Ipswich are genuinely like-for-like, because the size codes have barely moved in 25 years.
Installed prices by size
Each range below is supply and fit for a modern, thermally efficient roof window with a laminated inner pane. It includes the flashing kit matched to your covering, the insulation collar, the underfelt collar, all fixings, and reinstatement of the roof covering. Each assumes reasonable access, sound trimmers and no structural work.
| Job | Installed supply and fit | Days on site | Guarantee |
|---|---|---|---|
| Single unit up to MK06 (780 by 1180mm) | £1,150 to £1,650 | 1 | 10 years |
| Single unit PK10 or larger (940 by 1600mm up) | £1,450 to £2,100 | 1 | 10 years |
| Two units on the same slope | £2,000 to £2,900 | 1 to 2 | 10 years |
Structural opening dimensions shown for reference. Your survey confirms the opening and fixes the price. Full published pricing across every service is on our costs page.
The reason the figure sits inside a range rather than on a single number is that a roof window is not one product. Glass specification, the operating mechanism and the finish all move the unit price before access even enters the picture.
What moves the figure within the range
- Top hung instead of centre pivot: add roughly 15 to 30 per cent on the unit. Worth it where a desk or bed sits under the window, or where the room needs a fire escape.
- Triple glazing: add around 20 to 30 per cent on the unit. Compelling on a north slope in a room you heat hard, less so on a small landing.
- White painted or polyurethane finish: a modest add, and the right choice in any bathroom or humid room where bare pine would not last.
- Coastal specification: 316L stainless fixings and upgraded flashing are included as standard within a mile of open sea at Felixstowe, Harwich or Aldeburgh. It is not an upsell, it is what survives there.
The two variables to watch: access and making-good
Access
Access is quoted separately and it is the single biggest variable on a terrace. A window on a low single-storey rear slope can often be reached from a tower, which keeps the access cost small or removes it. A window at second-floor level on a Victorian terrace off Norwich Road needs full scaffold with a platform at eaves level, which is a real four-figure cost in its own right. We never roll access silently into the window price, and we never ask a homeowner onto the roof. The full picture is on our scaffolding page.
Making-good
Two things sit under this heading. The covering: a natural slate roof at Ipswich terrace level takes longer to strip and re-hang than a modern tile, and matching reclaimed slate for a Victorian roof adds materials and slower working so the patch does not read from the street. And the reveal: where internal plastering and decoration are in scope, that is priced and stated on the quote either way rather than assumed. One more, occasionally: if the strip-back reveals rotten trimmers, we photograph them and price the repair before proceeding, never quietly.
The survey confirms the exact figure, and that figure is then fixed. The ranges here are real, not a teaser. Once we have surveyed the roof you get one written price with the U-value stated on it, and that is what you pay, because the discovering happens at survey rather than halfway through the job.
Where this sits against the other cost questions
Replacing an existing window is the cheaper end of the roof-window work we do, precisely because nobody cuts the roof. Cutting a brand-new opening in a loft costs materially more, because it adds structural trimming, plastering, lining and Building Control; those figures are on our new opening cost page. And if you are weighing a glass-only swap against a full replacement, the frame-condition test that decides it is set out on our glass versus whole window page.
For the background on why these prices are built the way they are, the flashing kit, the two collars nobody quotes and the specification detail, see our fuller roof window installation cost guide. For how long the work keeps the roof open, see replacement time, and the full menu is on our published costs page.
No other installer in the area publishes these figures. We do, because three quotes with no common basis is a guess, not a comparison. The roof window installation hub explains the whole approach.
Request a fixed quote for a like-for-like roof window replacement in Ipswich, Suffolk or north Essex, and we will confirm your exact price after survey.
Thinking about this job? We survey across Ipswich, Suffolk and north Essex and give you a fixed price before any work starts, with a 10-year workmanship guarantee.